Optical processor

Abstract

Method and apparatus are disclosed for optical packet decoding, waveform generation, and wavelength multiplexing/demultiplexing using a programmed holographic structure. A configurable programmed holographic structure is disclosed. A configurable programmed holographic structure may be dynamically re-configured through the application of control mechanisms which alter operative holographic structures.

1. A method, comprising:
 forming a configurable programmed holographic structure in at least a portion of an optical medium, the holographic structure comprising a set of diffractive elements; 
 forming in the optical medium an input optical port for receiving into the holographic structure an input optical signal having an input spatial wavefront, an input optical spectrum, and an input temporal waveform; 
 forming in the optical medium an output optical port for transmitting from the holographic structure an output optical signal having an output spatial wavefront, an output optical spectrum, and an output temporal waveform; and 
 forming a control signal delivery structure operatively coupled to the holographic structure and arranged for altering the configuration of the configurable programmed holographic structure in response to an applied control signal; 
 arranging the diffractive elements of the set so that, before or after altering the configuration, the diffractive elements of the set are collectively arranged so as to comprise temporal, spectral, or spatial transformation information; 
 contouring and positioning each diffractive element of the set so that, before or after altering the configuration, each diffractive element of the set is individually contoured and positioned so as to reflectively image at least a portion of an input optical signal between the input optical port and the output optical port as the input optical signal propagates within the holographic structure; and 
 arranging the diffractive elements of the set so that, before or after altering the configuration, the diffractive elements of the set are collectively arranged for transforming the imaged portions of the input optical signal into the output optical signal according to the transformation information as the optical signals propagate within the holographic structure between the input optical port and the output optical port. 
 
     
     
       2. The method of  claim 1 , further comprising arranging the diffractive elements of the set so that the output spatial wavefront differs from the input spatial wavefront. 
     
     
       3. The method of  claim 1 , further comprising arranging the diffractive elements of the set so that the output optical spectrum comprises the input optical spectrum multiplied by a spectral transfer function portion of the transformation information. 
     
     
       4. The method of  claim 1 , further comprising arranging the diffractive elements of the set so that the output temporal waveform differs from the input temporal waveform. 
     
     
       5. The method of  claim 1 , further comprising arranging the diffractive elements of the set so that said transformation information comprises a cross-correlating transfer function. 
     
     
       6. The method of  claim 5 , further comprising arranging the diffractive elements of the set so that the cross-correlating transfer function comprises a complex conjugate of a Fourier transform of a reference waveform packet. 
     
     
       7. The method of  claim 5 , further comprising arranging the diffractive elements of the set so that the cross-correlating transfer function cross-correlates a temporal code of the input optical signal. 
     
     
       8. The method of  claim 5 , further comprising arranging the diffractive elements of the set so that said transformation information comprises a superposition of a plurality of cross-correlating transfer functions, the superposition forming a total cross-correlating transfer function. 
     
     
       9. The method of  claim 1 , further comprising:
 forming the configurable programmed holographic structure with a plurality of diffractive element sets; 
 forming a plurality of output optical ports each for transmitting from the holographic structure a corresponding output optical signal having a corresponding output spatial wavefront, a corresponding output optical spectrum, and a corresponding output temporal waveform; 
 arranging the diffractive elements of each set so that, before or after altering the configuration, the diffractive elements of each set are collectively arranged so as to comprise corresponding temporal, spectral, or spatial transformation information; 
 contouring and positioning each diffractive element of each set so that, before or after altering the configuration, each diffractive element of each set is individually contoured and positioned so as to reflectively image at least a portion of an input optical signal between the input optical port and the corresponding output optical port as the input optical signal propagates within the holographic structure; and 
 arranging the diffractive elements of each set so that, before or after altering the configuration, the diffractive elements of each set are collectively arranged for transforming the imaged portions of the input optical signal into the corresponding output optical signal according to the transformation information as the optical signals propagate within the holographic structure between the input optical port and the corresponding output optical port. 
 
     
     
       10. The method of  claim 9 , further comprising forming a photodiode array configured to receive the corresponding output optical signals from the plurality of output optical ports. 
     
     
       11. The method of  claim 10 , further comprising forming support electronics for the photodiode array. 
     
     
       12. The method of  claim 11 , further comprising integrating the holographic structure, the photodiode array, and the support electronics onto a monolithic substrate. 
     
     
       13. The method of  claim 10 , further comprising arranging the photodiode array for extracting data from the received output optical signals, and for outputting the extracted data. 
     
     
       14. The method of  claim 1 , further comprising arranging the diffractive elements of the set so that said transformation information comprises positional variation over some portion of the set of amplitude, optical separation, or spatial phase of the diffractive elements of the set. 
     
     
       15. The method of  claim 14 , further comprising:
 arranging the diffractive elements of the set so that, before altering the configuration, the diffractive elements of the set collectively exhibit positional variation in amplitude, optical separation, or spatial phase over some portion of the set; and 
 arranging the diffractive elements of the set so that, after altering the configuration, the diffractive elements of the set collectively exhibit altered positional variation in amplitude, optical separation, or spatial phase over some portion of the set. 
 
     
     
       16. The method of  claim 1 , arranging the diffractive elements of the set so that, before altering the configuration, the diffractive elements of the set collectively transform the imaged portions of the input optical signal into the output optical signal according to the transformation information as the optical signals propagate within the holographic structure between the input optical port and the output optical port. 
     
     
       17. The method of  claim 16 , arranging the diffractive elements of the set so that, after altering the configuration, the diffractive elements of the set collectively transform the imaged portions of the input optical signal into an altered output optical signal according to altered transformation information as the optical signals propagate within the holographic structure between the input optical port and the output optical port, the altered output optical signal differing from the output optical signal in temporal waveform, optical spectrum, or spatial wavefront. 
     
     
       18. The method of  claim 16 , further comprising arranging the diffractive elements of the set so that altering the configuration of the holographic structure results in substantial elimination of the output optical signal. 
     
     
       19. The method of  claim 1 , further comprising arranging the diffractive elements of the set so that, after altering the configuration, the diffractive elements of the set collectively transform the imaged portions of the input optical signal into the output optical signal according to the transformation information as the optical signals propagate within the holographic structure between the input optical port and the output optical port. 
     
     
       20. The method of  claim 19 , further comprising arranging the diffractive elements of the set so that the output optical signal is substantially absent before configuring. 
     
     
       21. The method of  claim 1 , wherein the input optical port and the output optical port comprise a common optical port. 
     
     
       22. The method of  claim 1 , wherein the input optical port and the output optical port comprise distinct optical ports. 
     
     
       23. The method of  claim 1 , wherein the optical medium comprises a planar waveguide substantially confining in one dimension the optical signals propagating in two dimensions therein. 
     
     
       24. The method of  claim 23 , further comprising arranging the planar waveguide and diffractive element of the set so that both the input optical signal and the output optical signal are substantially confined by the planar waveguide. 
     
     
       25. The method of  claim 23 , further comprising arranging the planar waveguide and the diffractive elements of the set so that only one of the input optical signal or the output optical signal is substantially confined by the planar waveguide. 
     
     
       26. The method of  claim 23 , further comprising arranging the planar waveguide and the diffractive elements of the set so that the input optical signal or the output optical signal propagates without confinement by the planar waveguide. 
     
     
       27. The method of  claim 23 , further comprising arranging the planar waveguide and the diffractive elements of the set so that the input optical signal or the output optical signal propagates in a direction with a substantially component along the confined dimension defined by the planar waveguide. 
     
     
       28. The method of  claim 1 , wherein the optical medium comprises a channel waveguide substantially confining in two dimensions the optical signals propagating therein. 
     
     
       29. The method of  claim 1 , further comprising forming the diffractive elements by photolithography, electron beam lithography, or etching, or combinations thereof. 
     
     
       30. The method of  claim 1 , further comprising forming the diffractive elements by stamping or embossing or combinations thereof. 
     
     
       31. The method of  claim 1 , wherein the control signal delivery structure comprises an energy delivery structure for introducing energy into the holographic structure to alter at least one optical characteristic thereof. 
     
     
       32. The method of  claim 31 , wherein the energy delivery structure comprises a conductive trace coupled to the configurable programmed holographic structure. 
     
     
       33. The method of  claim 32 , wherein at least one conductive trace is positioned and contoured so as to substantially correspond to one of the diffractive elements. 
     
     
       34. The method of  claim 32 , wherein:
 the energy delivery structure comprises multiple conductive traces; 
 the multiple conductive traces comprise at least two subsets; and 
 the energy delivery structure is adapted for enabling independent control of the introduction of energy through each subset of the multiple conductive traces. 
 
     
     
       35. The method of  claim 31 , wherein the modified optical characteristic is an index of refraction of at least one diffractive element. 
     
     
       36. The method of  claim 31 , further comprising forming the configurable programmed holographic structure as a plurality of segments, each segment comprising at least one diffractive element, each segment having an average index of refraction, wherein the modified optical characteristic is the average index of refraction of at least one segment. 
     
     
       37. The method of  claim 31 , further comprising forming the configurable programmed holographic structure as a plurality of segments, each segment comprising at least one diffractive element, each segment comprising a spatial structure, wherein the modified optical characteristic is the spatial structure of at least one segment. 
     
     
       38. The method of  claim 31 , further comprising forming the configurable programmed holographic structure as a plurality of segments, each segment comprising at least one diffractive element with at least one gap situated between adjacent segments, wherein the modified optical characteristic is a modified optical characteristic of at least one gap. 
     
     
       39. The method of  claim 38 , wherein the modified optical characteristic of at least one gap is the refractive index of material in the gap. 
     
     
       40. The method of  claim 38 , wherein the energy delivery structure comprises a conductive trace coupled to at least one gap. 
     
     
       41. The method of  claim 31 , further comprising forming the configurable programmed holographic structure as a plurality of segments, each segment comprising at least one diffractive element, at least one segment comprises a plurality of sub-segments, wherein the modified optical characteristic is a modified optical characteristic of at least one sub-segment. 
     
     
       42. The method of  claim 31 , wherein the energy delivery structure is adapted for introducing electromagnetic energy. 
     
     
       43. The method of  claim 42 , wherein the optical characteristic is modified by an electro-optic effect. 
     
     
       44. The method of  claim 31 , wherein the energy delivery structure is adapted for introducing thermal energy. 
     
     
       45. The method of  claim 31 , wherein the energy delivery structure is adapted for introducing photonic energy. 
     
     
       46. The method of  claim 31 , wherein the energy delivery structure is adapted for introducing acoustic energy. 
     
     
       47. The method of  claim 31 , wherein the energy delivery structure is adapted for introducing nuclear energy. 
     
     
       48. The method of  claim 31 , wherein the energy delivery structure is adapted for introducing chemical energy. 
     
     
       49. The method of  claim 1 , further comprising forming the configurable programmed holographic structure to act as a configurable de-multiplexer. 
     
     
       50. The method of  claim 1 , further comprising forming the configurable programmed holographic structure to act as a configurable multiplexer. 
     
     
       51. The method of  claim 1 , further comprising coupling control logic to the control signal delivery structure, wherein the holographic structure and the control logic are each integrated on an integrated circuit. 
     
     
       52. A method, comprising:
 forming a configurable programmed holographic structure comprising a set of diffractive elements; 
 forming an input optical port for receiving into the holographic structure an input optical signal having an input spatial wavefront, an input optical spectrum, and an input temporal waveform; 
 forming an output optical port for transmitting from the holographic structure an output optical signal having an output spatial wavefront, an output optical spectrum, and an output temporal waveform; and 
 forming means for altering the configuration of the configurable programmed holographic structure, 
 wherein, before or after altering the configuration: 
 the diffractive elements of the set are collectively arranged so as to comprise temporal, spectral, or spatial transformation information; 
 each diffractive element of the set is individually contoured and positioned so as to reflectively image at least a portion of an input optical signal between the input optical port and the output optical port as the input optical signal propagates within the holographic structure; and 
 the diffractive elements of the set are collectively arranged for transforming the imaged portions of the input optical signal into the output optical signal according to the transformation information as the optical signals propagate within the holographic structure between the input optical port and the output optical port. 
 
     
     
       53. The method of  claim 52 , further comprising forming means for introducing energy into the holographic structure to act as the means for altering the configuration of the configurable programmed holographic structure, the energy introducing means acting to alter at least one optical characteristic of the holographic structure.